fix: Deserialization checks valid class types for HttpTransportFactory

[lqiu96]

See b/479228571 for more information.

Attempts to resolve any deserialization issue when trying to create a new HttpTransportFactory. Validates so that a HttpTransportFactory implementation can be created to prevent arbitrary loading of classes (e.g. gadget classes that can execute commands).

Mimics the existing loading behavior in the constructor:

• Checks the ServiceLoader for any implementation
• Attempts to use the default
• Loads any custom implementation and tries to ensure that it's valid and loading doesn't run any static code.

[sonarqubecloud]

Quality Gate failed

Failed conditions
0.0% Coverage on New Code (required ≥ 80%)

See analysis details on SonarQube Cloud